<p>Provides any useful information about the protein, mostly biological knowledge.</p><p><a href='../manual/function_section' target='_top'>More...</a></p>Functionⁱ

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:</p><p><a href='../manual/gene_ontology' target='_top'>More...</a></p>GO - Molecular functionⁱ

1. identical protein binding Source: UniProtKB
2. structural molecule activity Source: InterPro
3. transmembrane signaling receptor activity Source: ProtInc

   <p>Traceable Author Statement</p> <p>Used for information from review articles where the original experiments are traceable through that article and also for information from text books or dictionaries.</p> <p>More information in the <a href="http://geneontology.org/page/guide-go-evidence-codes#tas">GO evidence code guide</a></p> Traceable author statementⁱ

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<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:</p><p><a href='../manual/gene_ontology' target='_top'>More...</a></p>GO - Biological processⁱ

1. calcium-independent cell-cell adhesion via plasma membrane cell-adhesion molecules Source: UniProtKB
2. establishment of skin barrier Source: UniProtKB

   <p>Inferred from Mutant Phenotype</p> <p>Describes annotations that are concluded from looking at variations or changes in a gene product such as mutations or abnormal levels and includes techniques such as knockouts, overexpression, anti-sense experiments and use of specific protein inhibitors.</p> <p>More information in the <a href="http://geneontology.org/page/guide-go-evidence-codes#imp">GO evidence code guide</a></p> Inferred from mutant phenotypeⁱ

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3. female pregnancy Source: Ensembl
4. response to progesterone Source: Ensembl
5. signal transduction Source: GOC

   <p>Traceable Author Statement</p> <p>Used for information from review articles where the original experiments are traceable through that article and also for information from text books or dictionaries.</p> <p>More information in the <a href="http://geneontology.org/page/guide-go-evidence-codes#tas">GO evidence code guide</a></p> Traceable author statementⁱ

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Enzyme and pathway databases

Protein family/group databases

<p>Provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.</p><p><a href='../manual/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyⁱ

Organism-specific databases

<p>Provides information on the location and the topology of the mature protein in the cell.</p><p><a href='../manual/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationⁱ

Topology

Feature key	Position(s)	Length	Description	Graphical view	Feature identifier	Actions
<p>Describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.</p><p><a href='../manual/topo_dom' target='_top'>More...</a></p>Topological domaini	1 – 7	7	CytoplasmicSequence Analysis
<p>Describes the extent of a membrane-spanning region of the protein. It denotes the presence of both alpha-helical transmembrane regions and the membrane spanning regions of beta-barrel transmembrane proteins.</p><p><a href='../manual/transmem' target='_top'>More...</a></p>Transmembranei	8 – 28	21	HelicalSequence Analysis			Add BLAST
<p>Describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.</p><p><a href='../manual/topo_dom' target='_top'>More...</a></p>Topological domaini	29 – 81	53	ExtracellularSequence Analysis			Add BLAST
<p>Describes the extent of a membrane-spanning region of the protein. It denotes the presence of both alpha-helical transmembrane regions and the membrane spanning regions of beta-barrel transmembrane proteins.</p><p><a href='../manual/transmem' target='_top'>More...</a></p>Transmembranei	82 – 102	21	HelicalSequence Analysis			Add BLAST
<p>Describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.</p><p><a href='../manual/topo_dom' target='_top'>More...</a></p>Topological domaini	103 – 117	15	CytoplasmicSequence Analysis			Add BLAST
<p>Describes the extent of a membrane-spanning region of the protein. It denotes the presence of both alpha-helical transmembrane regions and the membrane spanning regions of beta-barrel transmembrane proteins.</p><p><a href='../manual/transmem' target='_top'>More...</a></p>Transmembranei	118 – 138	21	HelicalSequence Analysis			Add BLAST
<p>Describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.</p><p><a href='../manual/topo_dom' target='_top'>More...</a></p>Topological domaini	139 – 160	22	ExtracellularSequence Analysis			Add BLAST
<p>Describes the extent of a membrane-spanning region of the protein. It denotes the presence of both alpha-helical transmembrane regions and the membrane spanning regions of beta-barrel transmembrane proteins.</p><p><a href='../manual/transmem' target='_top'>More...</a></p>Transmembranei	161 – 181	21	HelicalSequence Analysis			Add BLAST
<p>Describes the subcellular compartment where each non-membrane region of a membrane-spanning protein is found.</p><p><a href='../manual/topo_dom' target='_top'>More...</a></p>Topological domaini	182 – 209	28	CytoplasmicSequence Analysis			Add BLAST

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:</p><p><a href='../manual/gene_ontology' target='_top'>More...</a></p>GO - Cellular componentⁱ

1. apical plasma membrane Source: Ensembl
2. apicolateral plasma membrane Source: Ensembl
3. basal plasma membrane Source: Ensembl
4. integral component of plasma membrane Source: UniProtKB

   <p>Inferred from Mutant Phenotype</p> <p>Describes annotations that are concluded from looking at variations or changes in a gene product such as mutations or abnormal levels and includes techniques such as knockouts, overexpression, anti-sense experiments and use of specific protein inhibitors.</p> <p>More information in the <a href="http://geneontology.org/page/guide-go-evidence-codes#imp">GO evidence code guide</a></p> Inferred from mutant phenotypeⁱ

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5. lateral plasma membrane Source: Ensembl
6. plasma membrane Source: ProtInc

   <p>Traceable Author Statement</p> <p>Used for information from review articles where the original experiments are traceable through that article and also for information from text books or dictionaries.</p> <p>More information in the <a href="http://geneontology.org/page/guide-go-evidence-codes#tas">GO evidence code guide</a></p> Traceable author statementⁱ

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   • 9892664

7. tight junction Source: UniProtKB

   <p>Inferred from Direct Assay</p> <p>Used to indicate a direct assay for the function, process or component indicated by the GO term.</p> <p>More information in the <a href="http://geneontology.org/page/guide-go-evidence-codes#ida">GO evidence code guide</a></p> Inferred from direct assayⁱ

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<p>UniProtKB Keywords constitute a <a target="_top" href="/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='../help/keywords' target='_top'>More...</a></p>Keywords - Cellular componentⁱ

<p>Provides information on the disease(s) and phenotype(s) associated with the deficiency of a protein.</p><p><a href='../manual/pathology_and_biotech_section' target='_top'>More...</a></p>Pathology & Biotechⁱ

<p>Provides information on the disease(s) associated with genetic variations in a given protein. The information is extracted from the scientific literature and diseases that are also described in the <a href="http://www.ncbi.nlm.nih.gov/sites/entrez?db=omim"><span class="caps">OMIM</span></a> database are represented with a <a href="/diseases">controlled vocabulary</a> in the following way:</p><p><a href='../manual/involvement_in_disease' target='_top'>More...</a></p>Involvement in diseaseⁱ

CLDN4 is located in the Williams-Beuren syndrome (WBS) critical region. WBS results from a hemizygous deletion of several genes on chromosome 7q11.23, thought to arise as a consequence of unequal crossing over between highly homologous low-copy repeat sequences flanking the deleted region.

Mutagenesis

Feature key	Position(s)	Length	Description	Graphical view	Feature identifier	Actions
<p>Describes the effect of the experimental mutation of one or more amino acid(s) on the biological properties of the protein.</p><p><a href='../manual/mutagen' target='_top'>More...</a></p>Mutagenesisi	208 – 208	1	Y → F: Loss of phosphorylation by EPHA2. 1 Publication <p>Manually curated information for which there is published experimental evidence.</p> <p><a href="/manual/evidences#ECO:0000269">More…</a></p> Manual assertion based on experiment ini Ref.4 "EphA2 phosphorylates the cytoplasmic tail of Claudin-4 and mediates paracellular permeability." Tanaka M., Kamata R., Sakai R. J. Biol. Chem. 280:42375-42382(2005) [PubMed] [Europe PMC] [Abstract] Cited for: INTERACTION WITH EPHA2 AND TJP1, MUTAGENESIS OF TYR-208, PHOSPHORYLATION AT TYR-208 BY EPHA2.

<p>UniProtKB Keywords constitute a <a target="_top" href="/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='../help/keywords' target='_top'>More...</a></p>Keywords - Diseaseⁱ

Organism-specific databases

<p>Describes post-translational modifications (PTMs) and/or processing events.</p><p><a href='../manual/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingⁱ

Molecule processing

Feature key	Position(s)	Length	Description	Graphical view	Feature identifier	Actions
<p>Describes the extent of a polypeptide chain in the mature protein following processing.</p><p><a href='../manual/chain' target='_top'>More...</a></p>Chaini	1 – 209	209	Claudin-4		PRO_0000144743	Add BLAST

Amino acid modifications

Feature key	Position(s)	Length	Description	Graphical view	Feature identifier	Actions
<p>Specifies the position and type of each modified residue excluding <a href="/manual/lipid">lipids</a>, <a href="/manual/carbohyd">glycans</a> and <a href="/manual/crosslnk">protein cross-links</a>.</p><p><a href='../manual/mod_res' target='_top'>More...</a></p>Modified residuei	208 – 208	1	Phosphotyrosine; by EPHA21 Publication <p>Manually curated information for which there is published experimental evidence.</p> <p><a href="/manual/evidences#ECO:0000269">More…</a></p> Manual assertion based on experiment ini Ref.4 "EphA2 phosphorylates the cytoplasmic tail of Claudin-4 and mediates paracellular permeability." Tanaka M., Kamata R., Sakai R. J. Biol. Chem. 280:42375-42382(2005) [PubMed] [Europe PMC] [Abstract] Cited for: INTERACTION WITH EPHA2 AND TJP1, MUTAGENESIS OF TYR-208, PHOSPHORYLATION AT TYR-208 BY EPHA2.

<p>Describes post-translational modifications (PTMs). This subsection complements the information provided at the sequence level or describes modifications for which position-specific data is not yet available.</p><p><a href='../manual/post-translational_modification' target='_top'>More...</a></p>Post-translational modificationⁱ

<p>UniProtKB Keywords constitute a <a target="_top" href="/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='../help/keywords' target='_top'>More...</a></p>Keywords - PTMⁱ

Proteomic databases

PTM databases

<p>Provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.</p><p><a href='../manual/expression_section' target='_top'>More...</a></p>Expressionⁱ

Gene expression databases

Organism-specific databases

<p>Provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.</p><p><a href='../manual/interaction_section' target='_top'>More...</a></p>Interactionⁱ

<p>Provides information about the protein quaternary structure and interaction(s) with other proteins or protein complexes (with the exception of physiological receptor-ligand interactions which are annotated in the ‘Function’ section).</p><p><a href='../manual/subunit_structure' target='_top'>More...</a></p>Subunit structureⁱ

Protein-protein interaction databases

<p>Provides information on the tertiary structure of a protein.</p><p><a href='../manual/structure_section' target='_top'>More...</a></p>Structureⁱ

3D structure databases

<p>Provides information on sequence similarities with other proteins and the domain(s) present in a protein.</p><p><a href='../manual/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsⁱ

Region

Feature key	Position(s)	Length	Description	Graphical view	Feature identifier	Actions
<p>Describes a region of interest that cannot be described in other subsections.</p><p><a href='../manual/region' target='_top'>More...</a></p>Regioni	1 – 103	103	Interaction with EPHA2			Add BLAST
<p>Describes a region of interest that cannot be described in other subsections.</p><p><a href='../manual/region' target='_top'>More...</a></p>Regioni	208 – 209	2	Interactions with TJP1, TJP2 and TJP3By similarity

<p>Provides information about the sequence similarity with other proteins.</p><p><a href='../manual/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesⁱ

<p>UniProtKB Keywords constitute a <a target="_top" href="/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='../help/keywords' target='_top'>More...</a></p>Keywords - Domainⁱ

Phylogenomic databases

Family and domain databases

<p>Displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including length and molecular weight.</p><p><a href='../manual/sequences_section' target='_top'>More...</a></p>Sequenceⁱ

<p>Indicates if the canonical sequence displayed by default in the entry is complete or not.</p><p><a href='../manual/sequence_status' target='_top'>More...</a></p>Sequence statusⁱ: Complete.

        10         20         30         40         50
MASMGLQVMG IALAVLGWLA VMLCCALPMW RVTAFIGSNI VTSQTIWEGL 
        60         70         80         90        100
WMNCVVQSTG QMQCKVYDSL LALPQDLQAA RALVIISIIV AALGVLLSVV 
       110        120        130        140        150
GGKCTNCLED ESAKAKTMIV AGVVFLLAGL MVIVPVSWTA HNIIQDFYNP 
       160        170        180        190        200
LVASGQKREM GASLYVGWAA SGLLLLGGGL LCCNCPPRTD KPYSAKYSAA 

RSAAASNYV                                             

Sequence databases

Genome annotation databases

<p>Is used to point to information related to entries and found in data collections other than UniProtKB.</p><p><a href='../manual/cross_references_section' target='_top'>More...</a></p> Cross-referencesⁱ

<p>Provides links to various web resources that are relevant for a specific protein.</p><p><a href='../manual/web_resource' target='_top'>More...</a></p> Web resourcesⁱ

Sequence databases

3D structure databases

Protein-protein interaction databases

Protein family/group databases

PTM databases

Proteomic databases

Protocols and materials databases

Genome annotation databases

Organism-specific databases

Phylogenomic databases

Enzyme and pathway databases

Miscellaneous databases

Gene expression databases

Family and domain databases

<p>Contains the literature citations that are the sources of data used to annotate the entry. Each reference is numbered and contains several subsections allowing a precise description of a given citation.</p><p><a href='../manual/publications_section' target='_top'>More...</a></p>Publicationsⁱ

1. "Clostridium perfringens enterotoxin utilizes two structurally related membrane proteins as functional receptors in vivo."
   Katahira J., Sugiyama H., Inoue N., Horiguchi Y., Matsuda M., Sugimoto N.
   J. Biol. Chem. 272:26652-26658(1997) [PubMed] [Europe PMC] [Abstract]
   Cited for: NUCLEOTIDE SEQUENCE [MRNA].
   Tissue: Fetal brain.
   
2. "Cloning of human full-length CDSs in BD Creator(TM) system donor vector."
   Kalnine N., Chen X., Rolfs A., Halleck A., Hines L., Eisenstein S., Koundinya M., Raphael J., Moreira D., Kelley T., LaBaer J., Lin Y., Phelan M., Farmer A.
   Submitted (MAY-2003) to the EMBL/GenBank/DDBJ databases
   Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
3. "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
   The MGC Project Team
   Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]
   Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
   Tissue: Colon.
   
4. "EphA2 phosphorylates the cytoplasmic tail of Claudin-4 and mediates paracellular permeability."
   Tanaka M., Kamata R., Sakai R.
   J. Biol. Chem. 280:42375-42382(2005) [PubMed] [Europe PMC] [Abstract]
   Cited for: INTERACTION WITH EPHA2 AND TJP1, MUTAGENESIS OF TYR-208, PHOSPHORYLATION AT TYR-208 BY EPHA2.
5. "Initial characterization of the human central proteome."
   Burkard T.R., Planyavsky M., Kaupe I., Breitwieser F.P., Buerckstuemmer T., Bennett K.L., Superti-Furga G., Colinge J.
   BMC Syst. Biol. 5:17-17(2011) [PubMed] [Europe PMC] [Abstract]
   Cited for: IDENTIFICATION BY MASS SPECTROMETRY [LARGE SCALE ANALYSIS].

<p>Provides general information on the entry.</p><p><a href='../manual/entry_information_section' target='_top'>More...</a></p>Entry informationⁱ

<p>Contains any relevant information that doesn’t fit in any other defined sections</p><p><a href='../manual/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousⁱ

<p>UniProtKB Keywords constitute a <a target="_top" href="/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='../help/keywords' target='_top'>More...</a></p>Keywords - Technical termⁱ

Documents

1. Human chromosome 7
   Human chromosome 7: entries, gene names and cross-references to MIM
2. MIM cross-references
   Online Mendelian Inheritance in Man (MIM) cross-references in UniProtKB/Swiss-Prot
3. SIMILARITY comments
   Index of protein domains and families

External Data

<p>Provides links to the UniProt Reference Clusters (<a href="/help/uniref">UniRef</a>). UniRef consists of clusters for UniProtKB sequences (including isoforms) and selected UniParc sequences, in order to obtain complete coverage of the sequence space at resolutions of 100%, 90% and 50% identity.</p><p><a href='../manual/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsⁱ